Educational appliance



March 20, 1934. BAKST 1,951,337

EDUCATIONAL APPLIANCE Filed NOV. 24, 1950 RED 1/ 1? 1 RED YELLOW 4/29 57 YELLOW YELL 8Row- 5 0W 40- 0 ELz/E 4 YECLO w YELLOW LUE RED I 6 029 405 YELLOW o YELLOW BLUE fru ezztar jiforne y Patented Mar. 20, 1934 EDUCATIQNAL APPLEANCE Application November 24, 1930, Serial No. 497,883

3 Claims.

The present invention relates to an educational device, and has for an object to provide a figure so constructed as to illustrate various basic geometrical and other mathematical theorems and propositions.

The invention aims to provide a structural form or figure which may be used by the professor or teacher in the classroom or lecture hall, or which may be used by the student alone, to demonstrate physically certain basic propositions and geometrical facts so that they may be more quickly and thoroughly understood and so that they may be indelibly impressed on the mind in the handling and observance of the actual structures.

Another object of the invention is to provide a geometrical figure constructed with certain substantially transparent or reticulated parts through which may be easily observed other and interior parts so that the angular relations between the parts of the figure may be observed.

A further object of the invention is to provide a geometrical construction which admits of the use of contra-distinguishing colors of the various parts of the figure by which the observer may more easily observe the parts in their relation to one another.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawing,

Figure 1 is a perspective view of a geometrical figure constructed according to the present invention and showing a plane bisecting a dihedral angle.

Figure 2 is a top plan view of the same.

Figure 3 is a side elevation thereof.

Figure is an end elevation.

Referring now to the drawing, 35 designates an angle member which is, in the present instance, in the form of a dihedral and which may be constructed of a screen or other transparent sheet body portion bent intermediate its ends upon a transverse line 36 and with the opposite ends of the angle member providing wings which diverge upwardly from the line of bend 36. This angle member may be constructed of wire meshing with a suitable marginal edge frame of wire, of channeled metal strip, or casting material, or of any other suitable and adaptable configuration and material to provide a suitable binding for the protection of the wire meshing.

Seated at its lower edge within the angle men ber 35 and substantially co -incident with the line of bend 36, is a frame member 37 which may also be constructed of wire meshing similar to the angle member 35 but which is relatively flat and which may be constructed in any suitable manner to admit observation through 90 the frame member 3'7. The frame member 37 is provided intermediate its opposite ends with a vertically disposed slot 38 which is of less height than that of the frame member 37 and through which engages a transverse frame member 39 05 adapted to seat at its intermediate lower edge portion in the bend of the angle member 35 and which has its lower edge beveled and diverging upwardly to conform to the upwardly diverging planes of the opposite ends of the angle member 35.

Rods or bars 40 are preferably mounted in the transverse plane member 39 and diverging downwardly from the point of intersection of the plane members 37 and 39 to the points of intersection of the lateral wings of the angle member 35 with the lower edge portions of the transverse plane member 39. The upper ends of the rods 40 converge to a point of intersection between the planes 37 and 39 so that certain propositions, theorems and other facts and problems presented in geometry and mathematics may be readily demonstrated.

All of the various planes and wings are preferably constructed of transparent material, such 5 as screen or the like, so that the various lines and points of intersection may be observed and so that, if necessary or desired, various actual measurements may be taken along the various edges or lines presented incident to the points of in- 9Q tersection or relative distances of points from different positions in the planes.

This structural figure is adapted to be used for demonstrating certain basic propositions in geometry and among which may be mentioned; to demonstrate that the locus of all points equidistant from the faces of a dihedral angle is in a plane bisecting that angle, and that every point in a plane bisecting a dihedral angle is equidistant from the faces of that angle.

It will also be noted from the drawing that the various planes and Wings and other parts may be given contra distinguishing colors so as to more forcibly emphasize the relation between the parts and to permit the observer to more 1125 readily follow the courses defined by the various planes and lines of intersection, and also the location of the various points which are to be considered in the demonstration.

The angle member 35 may be of a blue color, lie

the vertical bisecting plane member 37 may be of a red color, while the transverse intersecting plane 39 may be of a yellow color, and the rods or bars 40 may be of a brown color. Of course various other color arrangements or schemes may be resorted to, the above being shown and described merely by way of example as to how one color scheme may be used.

The above described figure may be used for demonstrating not only certain basic propositions in geometry, but also their related corollaries.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:-

1. An article of manufacture for physically illustrating mathematical problems, comprising a pair of transparent plane plates disposed in edgewise abutting relation and forming a dihedral angle between them, and a pair of right angularly intersecting substantially transparent plane plates arranged within the angle of said first plates and with one of the intersecting plates in position bisecting the dihedral angle, the inner edge portions of the other said intersecting plate conforming to and abutting against the face portions of said first plates to show the lines rods carried by said transverse plate and diverging downwardly in opposite directions from the line of intersection of the transverse plate with the bisecting plate to the lower edge portions of said intersecting plates.

3. An article of manufacture comprising a plurality of relatively fixed, substantially transparent members, each having a reinforced perimeter, one of said members consisting of plane portions angularly related to define a dihedral angle between them, a second member symmetrically related to said portions within said defined angle and engaging with and extending longitudinally of the apex of said angle, and a third member engaging said plane portions within the angle defined thereby and disposed at an angle to and intersecting said second member.

AARON BAKST. 

